As an electronic equipment cabinet for efficiently storing a circuit board unit, there is known a cabinet that includes slots to freely insert and extract circuit board units.
Arranging cover members in the circuit board units to cover the slot provides an advantage of simultaneously storing the circuit boards and closing the slots. Such an electronic equipment cabinet is generally employed for a personal computer and, in many cases, employed for a video device and a measuring device.
When the electronic equipment cabinet having the slots is employed for the video device, a gap between an outer wall of the cabinet and the cover member of the circuit board unit creates a possibility that EMI (Electro Magnetic Interference), such as electromagnetic wave leakage to the outside of the cabinet, may occur. JP2000-332479A (Patent Literature 1) discloses a method for improving the effects of reducing EMI by forming a gasket in the gap between the cabinet and the cover member to close the gap, thereby improving shielding performance.
In recent years, for security purposes, there has been known an electronic equipment cabinet that includes a switch to detect storage of a circuit board unit in a slot of the cabinet. JP2004-172455A (Patent Literature 2) discloses an electronic equipment cabinet that includes a switch and can detect a storage state or a load state based on the contact state between a part of the cover member and the switch.
In the electronic equipment cabinet for storing the plurality of circuit board units, the inclusion of a switch corresponding to each circuit board unit increases the number of components, thus increasing costs. The switch itself becomes an EMI antenna, and hence when there are many switches, the influence of EMI easily appears.
In particular, the recent enlargement of the video device requires displaying of a video with higher accuracy and smoother representation of motion. This necessitates video data of a wider band, and a clock of the video device has become faster. The faster clock generates greater noise, and the influence of EMI has become more conspicuous in the video device.